Endothelin is a potent constrictor of human vessels used in coronary revascularization surgery.
We studied the interaction of endothelin and endothelium-derived relaxing factor (EDRF) in human saphenous veins and internal mammary arteries using isolated ring preparations. Endothelin was a more potent constrictor of human internal mammary arteries and saphenous veins than norepinephrine. The ability of acetylcholine to reverse endothelin-induced contraction was greater in the internal mammary arteries than in saphenous veins. However, nitroprusside produced similar and near-complete inhibition of endothelin precontraction in both arteries and veins. We conclude that endothelin is a potent constricting agent in human internal mammary arteries and saphenous veins in vitro. Endothelin-induced vasoconstriction is effectively inhibited by EDRF, but human saphenous veins appear to have limited capability for endothelium-dependent dilation.
Costello
K B
KB
Department of Medicine, McGill University, Montreal, Canada.
Stewart
D J
DJ
Baffour
R
R
D000109:Acetylcholine / Q000494:pharmacology; D001026:Coronary Artery Bypass; D016232:Endothelins / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D008323:Mammary Arteries / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009599:Nitroprusside / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D012501:Saphenous Vein / Q000187:drug effects; D014662:Vasoconstrictor Agents
D016232:Endothelins; D014662:Vasoconstrictor Agents; D009599:Nitroprusside; D000109:Acetylcholine; D009638:Norepinephrine